Is it safe to take heart medications, blood thinners, and blood pressure medicine with penicillin?

Yes: Yes, in general penicillen has no negative interactions. But make sure the prescribing physician has a complete list of all your medications, supplements, and over the counter medications.

Yes unless....: Yes unless the blood thinner is coumadin (warfarin). All antibiotics can interact with Coumadin (warfarin) to raise its effect, so an earlier blood test is needed.